If $x \oslash y = x-3y$ and $x \bigtriangledown y = 8y+4$, find $(1 \oslash -5) \bigtriangledown 2$.
Solution: We don't need to find $1 \oslash -5$ because $x \bigtriangledown y$ depends only on the right operand. Find $x \bigtriangledown 2$ $ x \bigtriangledown 2 = (8)(2)+4$ $ \hphantom{x \bigtriangledown 2} = 20$.